Hypodermic needle with retractable tip



Oct. 17, 1967 A. GINSBURG 3,347,232

HYPODERMIC NEEDLE WITH RETRACTABLE TIP Filed April 26, 1965 IN VENTOR.

Abraham Ginsburg BY WWW ATTORNEY-5 United States Patent 3,347,232HYPODERMIC NEEDLE WITH RETRACTABLE TIP Abraham Ginsburg, 4031 SheflieldAve., Philadelphia, Pa. 19136 Filed Apr. 26, 1965, Ser. No. 450,595Claims. (Cl. 128-221) ABSTRACT OF THE DISCLOSURE This invention relatesto a hypodermic needle whose primary object is to provide a retractablepointed insertion tip and releasable means to hold it rigidly in placeon the shank for insertion into a blood vessel so that after insertion,when the patient moves and the tip strikes the vessel wall, it willretract on the shank to thereby eliminate pain and injury to the vesselwall.

Another object of the invention is to provide a hypodermic needle withretractable tip of the character above described in which the releasablemeans to hold the tip in a rigid position for insertion into a bloodvessel is a blood soluble adhesive so that the tip is free to retract oncontact with the vessel wall within a relatively short time afterinsertion into the vessel.

Another object is to provide a hypodermic needle of the characterdescribed combining aretractable insertion tip and a new and improvedmeans to lock the same under the skin or subcutaneous tissue and thusrestrain to'and fro movement of the needle, thereby permitting morefreedom of movement of the patient without fear of pain and injury tothe blood vessel or dislodgement of the needle. 1

Another object of the invention is to provide a hypodermic needle of thecharacter described with a new and improved angulated retractableinsertion point which militates against accumulation of blood in apocket around the needle when the tip is in its retracted position.

Another object of the invention is to provide a hypodermic needle with aretractable tip and locking means which is economical to manufacture andrelatively easy to insert into and remove from a blood vessel.

These and other objects of the invention will become more apparent asthe following description proceeds in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is an elevational view of the needle embodying the invention perse;

FIG. 2 is an enlarged vertical sectional view through the forward end ofthe needle and illustrating the insertion position of the needle;

FIG. 3 is an end elevational view of the needle looking from line 33 inFIG. 2;

FIG. 4 is an enlarged vertical sectional view of the insertion tipretracted upon the shank of the needle;

FIG. 5 is an enlarged side elevational view of the locking collarmounted on the shank with parts broken away and shown in verticalsection to illustrate details;

FIG. 6 is a side elevational view of the needle shown inserted in a veinand locked in the skin with the insertion tip retracted upon the shankwith parts broken away and shown in vertical section to illustratedetails; and

3,347,232. Patented Oct. 17, 1967 FIG. 7 is an enlarged verticalsectional view of a modified form of insertion tip shown retracted uponthe shank.

Specific reference is now made to the drawings wherein similar referencecharacters are used for corresponding elements throughout.

The hypodermic needle of the instant invention comprises a substantiallycylindrical shank 10 with a uniform bore 12 therethrough whichterminates at its forward end 14 in a non-pointed edge which lies in aplane substantially normal to the axis of the bore. A radially extendinglip 16 is provided at the top of edge 14, the purpose of which willappear hereinafter. At the other or rear end of the shank there issecured or integral thereat an adapter 18 for attachment to a syringe ora tube connected to a suspended container having an injectable fluidtherein, as is well known in the art.

At the forward end 14 of the shank, a substantially cylindrical hollowinsertion tip 20 is mounted for sliding movement on said shank, theforward end of the tip being cut at an angle to its axis to form anangulated pointed edge. The rearmost portion of the pointed edge of saidtip is a shoulder 24 which is adapted to abut the lip 16 and preventfurther forward movement of the tip off the shank. In this position, asseen in FIG. 2, the pointed edge 22 extends beyond the non-pointed edgeof the shank and is ready for insertion into a blood vessel.

A releasable means is provided to hold the tip rigidly during insertioninto a blood vessel. The means is preferably a blood soluble adhesive 26which is placed against the rear edge 28 of the tip itself and againstthe adjacent area of the shank. To assist in placing the adhesive inproper position, a well or indentation 30 is provided in the shank at aposition adjacent the rear edge 26 of the tip when the latter is in itsforwardmost position with the portion 24 of its pointed edge abuttingthe stop lip 16. The blood soluble adhesive is preferably an equalmixture by volume of dextrin, gelatin, and water which is kept viscousat -200 F. and inserted in the viscous state into the well 30. When itsolidifies, it causes the tip 20 to adhere to the shank 10.

A locking means is provided to engage the skin and restrain to and fromovement of the needle when it is in position in the blood vessel, whichlocking means obviates the necessity of using tie-downs, such as tape,rubber tubing, etc. This locking means comprises a collar 32 on theshank adjacent the adapter 18 which cooperates with the adapter. Theforward Wall 34 of the adapter is preferably substantially normal to theshank axis and has a diameter which exceeds the outer diameter of theshank. The collar is formed of a band of knife edge cross section (seeFIG. 5) which is wrapped around the shank and clinched in place so thatits outer surface 36 tapers away from the adapter and towards theinsertion tip. At its widest diameter which approximates the outerdiameter of the tip 20, the collar is inwardly beveled to form acountersunk shoulder 38 which is spaced from and faces the shoulder 34of the adapter, the portion of the shank between the shoulders beingindicated at 40.

In use, the needle with the tip releasably held in the position shown inFIG. 2 is inserted through the skin 42 and moved therebeneath throughthe subcutaneous tissue 43. The insertion tip 20 pierces wall 44 of thevein or other blood vessel and moves into the vessel. As the tip piercesthe vessel, the skin 42 slides over the tapered surface 36 of thecollar, the puncture in the skin gradually enlarging until it reachesand rides over the shoulder 38 where it contracts to the diameter of theshank 10 at section 40. The skin is thus locked in place between theshoulder 38 of the collar and the shoulder 34 of the adapter, therebygreatly minimizing to and fro movement longitudinally between the needleand the skin even if the limb or other part of the body is frequentlymoved. The outer surface 36 of the collar 32 is tapered towards the tip,and its diameter approximates that of the tip to ease the action ofinserting and removing the needle.

After the insertion tip 20 is in the blood vessel for a short period,such as a few minutes, the adhesive 26 dis solves, thereby freeing theinsertion tip 20 for axial or longitudinal movement along the shank 10.Thus, if the forward pointed edge 22 of the tip touches or abuts thevessel wall 44, it immediately retracts upon the shank. This removes thepain and damage normally caused by the needle scratching and piercingthe vessel wall in the conventional construction which employed a fixedinsertion tip. As shown in FIG. 6, the tip can move back on the shankfar enough so that only the non-pointed edge 14 of the shank will beexposed, and if this touches the vessel wall, it will not causescratching and attendant pain.

A modification of the insertion tip 20 is shown in FIG. 7. Themodification is to thepoint of the needle at its pointed edge 22. Asseen in FIG. 4, at the edge 22 of the tip 20, a pocket 46 is formedbetween the edge 22 and the outer surface ofshank when the tip is in itsretracted position with the non-pointed edge 14 of the shank extendingbeyond the pointed edge 22 of the tip. Although this pocket is small, itpresents thepossibility of undesirable accumulation of blood therein. Inorder to overcome this, the insertion point, as seen in FIG. 7, isformed by cutting the insertion tip at an angle with the axis thereofreversely to the angle of cut of the edge 22 to form a chamfer 48peripherally around said edge 22. The result is that the chamfer 48tapers towards the shank 10 and terminates in a peripheral edge 50 whichis'flush against the shank, thus eliminating the accumulation pocket 46of the form shown in FIG. 4.

In practice, it has been found that good results are attained using anl8-gauge needle whose bore has a diameter of .030 inch and whose shankhas an outer diameter of .050 inch along its entire length. Theinsertion tip 20 is made from 17-gauge tubing, and the tapered collar 32has a maximum outer diameter at its shoulder 38 of .070 inch, and theshoulder 38 is spaced inch from the shoulder 34 of adapter 18. -It isunderstood, however, that the invention is, of course, applicable toneedles of other dimensions.

A skilled artisan may make minor variations without departing from thespirit of the invention and the scope of the appended claims.

I claim:

1. A hypodermic needle comprising an elongated hollow shank having anon-pointed end, a hollow retractable insertion tip having a pointed endand mounted for axial movement on said shank and releasable meansretaining said insertion tip in a forward position where said pointedend thereof extends beyond said non-pointed end of said shank forinsertion into a blood vessel, said releasable means including a bloodsoluble adhesive so that after insertion in the vein and dissolution ofsaid adhesive abutment of said tip with the blood vessel wall will causesaid tip to retract to a point where only the non-pointed end ofsaidshank will be exposed.

2. The needle of claim'l and stop means at said nonpointed end of saidshank to prevent said insertion tip from sliding olr saidshank in aforward direction.

3. The needle of claim 2 and a well in the surface of said shankadjacent to said tip when the latter is in its forwardniost position toreceive said adhesive for engagement with said tip.

4. A hypodermic needle comprising an elongated hollow substantiallycylindrical shank having anon-pointed forward end, a substantiallycylindrical hollow retractable tip mounted for sliding movement on saidshank,-and having a pointed end wall adapted for insertion into a bloodvessel, stop means limiting outward movement of said tip to apredetermined position where said pointed end thereof extends beyondsaid non-pointed end of said shank, and blood soluble adhesive meansreleasably retaining said tip in said predetermined position.

5. The needle of claim 4 wherein said pointed end wall of said tip liesin a plane which is at an acute rearward angle to the axis of said tipand a chamfer peripherally around said end wall tapering forwardly ofsaid tip to eliminate formation of a clogging pocket between said tipand said shank when said tip is retracted to a position wherein itspointed end is rearward of said non-pointed end of said shank.

References Cited UNITED STATES PATENTS 1,087,845 2/1914 Stevens 128-2213,099,988 8/1963 Ginsberg an 128-221 3,204,634 9/1965 Koehn 128221RICHARD A. GAUDET, Primary Examiner.

D. L. BAKER, Assistant Examiner.

4. A HYPODERMIC NEEDLE COMPRISING AN ELONGATED HOLLOW SUBSTANTIALLYCLYINDRICAL SHANK HAVING A NON-POINTED FORWARD END, A SUBSTANTIALLYCYLINDRICAL HOLLOW RETRACTABLE TIP MOUNTED FOR SLIDING MOVEMENT ON SAIDSHANK, AND HAVING A POINTED END WALL ADAPTED FOR INSERTION INTO A BLOODVESSEL, STOP MEANS LIMITING OUTWARD MOVEMENT OF SAID TOP TO APREDETERMINE POSITION WHERE SAID POINTED END THEREOF EXTENDS BEYOND SAIDNON-POINTED END OF SAID SHANK, AND BLOOD SOLUBLE ADHESIVE MEANSRELEASABLY RETAINING SAID TIP IN SAID PREDETERMINE POSITION.